One special application of this invention is for windows that are installed in roofs, such as for loft or attic conversions, and where it is required under Statutory Regulations or Codes of Practice that a means of escape for an emergency be provided from such room.
It is already known to provide windows of the type in which there is a fixed outer frame that is secured to the structure and which fixed frame mounts a glazed sash for pivotal movement by means of pivot hinges defining a horizontal axis about which the sash pivots relative to the frame. Commonly such pivot hinges are known as horizontal pivots, and there are many kinds of such pivots which are designed for particular uses and styles of windows.
Typically, such horizontal pivots may incorporate devices to limit pivotal movement so that the sash can be held or secured in a vent position and cannot be fully opened until the device is released. In addition, some horizontal pivots are designed, in conjunction with design of the sash and fixed frame, to provide for an extended range of pivotal movement to enable the sash to be reversed for cleaning.
Irrespective of the wide range of types of such horizontal pivots, they are all designed to support the sash for such horizontal pivoting movement about the horizontal axis which extends substantially across the middle of the glazed sash. Thus, even when the sash is fully open or reversed, the opening through the structure defined by the fixed outer frame is obstructed by the glazed sash, and such opening will not fulfill the requirements for an emergency or escape access from the building.
It is already known to provide horizontal pivots in which the pivot assembly has two main parts respectively secured to the frame and the sash, and these parts can be separated so as to uncouple them to permit removal of the sash from the fixed frame. Various types of these pivots are known and are commonly called sash lift-off pivots. As will be appreciated, although such lift-off pivots permit the fixed frame to be revealed as an open access opening by removal of the sash, such method of providing an access opening is not suitable for emergncy or escape purposes. These lift-off pivots are designed for window systems only to facilitate maintenance and any re-glazing, and the sash is removed inwardly of the fixed frame into the structure. Thus, such lift-off pivots are not suitable for escape or emergency requirements where a full outward opening is required by a simple operation of some suitable actuator.